Magnetic systems for electronic devices and accessories

ABSTRACT

A cover is described that is magnetically attached to a tablet device. The cover includes at least as flap. In the described embodiment, the flap includes a plurality of segments where the first segment includes a first plurality of edge attach magnets arrayed along a first edge of the flap and where a second segment includes a second plurality of edge attach magnets arrayed along a second edge of the flap opposite the first edge.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) to U.S.Provisional Patent Application No. 61/681,117, filed Aug. 8, 2012 andentitled “Consumer Electronic Product” by Sartee et al., which areincorporated by reference in their entirety for all purposes.

FIELD OF THE DESCRIBED EMBODIMENTS

The described embodiments generally relate to portable electronicdevices. More particularly, the present embodiments describe variousreleasable attachment techniques well suited for portable electronicdevices.

DESCRIPTION OF THE RELATED ART

Recent advances in portable computing includes the introduction of handheld electronic devices and computing platforms along the lines of theiPad™ tablet manufactured by Apple Inc. of Cupertino, Calif. Thesehandheld computing devices can be configured such that a substantialportion of the electronic device takes the form of a display assemblyused for presenting visual content. The display assembly generallyincludes an active display area configured to present visual content anda top protective layer used to provide protection against externaleffects, such as would be expected during normal use. However, in somecases, additional protection can be afforded both the tablet device anddisplay assembly using a separate accessory device that takes the formof a protective cover attached to the tablet device. However, due to therelatively large size of the display in relation to the tablet device asa whole, little space is available for attaching the protective cover tothe tablet device.

Moreover, conventional attachment mechanisms such as mechanicalfasteners, clasps, and so forth typically require an externallyaccessible attaching feature on the electronic device to mate with acorresponding attaching feature on the accessory device. Thisarrangement can detract from the overall look and feel of the handheldcomputing device as well as add unwanted weight and complexity as wellas degrade the appearance of the hand held computing device.

Therefore what is desired are magnetic systems that facilitate the useof an accessory device with a tablet device.

SUMMARY OF THE DESCRIBED EMBODIMENTS

This paper describes various embodiments that relate to a system,method, and apparatus for releasably attaching an accessory to anelectronic device.

A magnetic system suitable for use in a protective cover having afoldable flap formed of a layer of finishing material, the protectivecover used in cooperation with a tablet device having a display isdescribed. The magnetic system includes at least a first array of edgeattach magnets aligned with a first edge of the foldable flap cover, asecond array of edge attach magnets aligned with a second edge of thefoldable flap and aligned with the first array of edge attach magnets,wherein the first and second array of edge attach magnets form amagnetic circuit that maintains a folded configuration of the protectivecover, and a plurality of field shaping magnets disposed at selectedlocations on the magnetic cover such that magnetic fields from theplurality of field shaping magnets interact with magnetic fields fromthe first array of edge attach magnets to effectively provideessentially a null magnetic field at least one predefined positioncorresponding to a magnetically sensitive circuit disposed in the tabletdevice.

In another embodiment a consumer system is described. The consumersystem includes at least a tablet device that includes a housing havinga front opening, a display assembly disposed within the front openingthat includes a display and a top protective layer disposed adjacent tothe display. The tablet device also includes a plurality of sensorsconfigured to detect a corresponding stimulus, and a first magneticattachment system disposed within and secured to an inside side wall ofthe housing, the first magnetic attachment system configured to providea variable magnetic surface at an exterior of the housing in response toan appropriately configured external magnetic field. The consumer systemalso includes a cover, that includes at least a segmented flap formed ofa layer of protective finishing material having a size and shape inaccordance with the display, an integrated hinge comprising a flexiblehinge formed of a continuous layer of the layer of finishing material,and a second magnetic attachment unit configured to provide theappropriately configured magnetic field to the first magnetic attachmentsystem, wherein the first magnetic attachment system interacts with theappropriately configured magnetic field by transitioning from aninactive state to an active state, wherein in the active state the firstmagnetic attachment system provides a first magnetic surface at anexterior of the housing suitable for forming a magnetic attachment withthe second magnetic attachment system.

In yet another embodiment a method of magnetically attaching a tabletdevice and a protective cover is described. The tablet device includes ahousing and a first magnetic attachment system having a first pluralityof magnets and a magnetic shield disposed between the first plurality ofmagnets and an interior of a first side wall of the housing and theprotective cover includes a second magnetic attachment system having asecond plurality of magnets. The method is carried out by causing thefirst magnetic attachment system to transition from an inactive state toan active state, and forming a magnetic attachment between the firstmagnetic attachment system and the second magnetic attachment system inresponse to the transition to the active state.

Other aspects and advantages of the invention will become apparent fromthe following detailed description taken in conjunction with theaccompanying drawings which illustrate, by way of example, theprinciples of the described embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 is a simplified block diagram of an article and an electronicdevice that can be releasably attached to each other in a desired andrepeatable manner.

FIG. 2A is a simplified perspective view of an article that can bereleasably attached to an electronic device via a side magneticattachment system, in accordance with one described embodiment.

FIG. 2B shows the article and the electronic device of FIG. 2A attachedin accordance with the side magnetic attachment system.

FIG. 3A is a simplified perspective view of an article that isreleasably attachable to an electronic device via a top magneticattachment system in accordance with one described embodiment.

FIG. 3B shows the article and the electronic device of FIG. 3Amagnetically attached to each to each other to form a cooperating systemusing the top magnetic attachment system.

FIG. 4A is a simplified perspective view of an article that isreleasably attachable to an electronic device via the top and sidemagnetic attachment systems.

FIG. 4B shows a cooperating system of the attached article and theelectronic device shown in FIG. 4A in a closed configuration.

FIG. 4C shows the cooperating system of FIG. 4B in an openconfiguration.

FIG. 5 shows a top perspective view of an electronic device inaccordance with the described embodiments.

FIG. 6 shows another embodiment of a magnetic attachment feature.

FIG. 7A shows an electronic device in proximity to another object in theform of an accessory device having a magnetic attachment feature.

FIG. 7B shows a graphical representation of a cooperating system formedby the magnetic attachment of the accessory device and the electronicdevice as shown in FIG. 7A.

FIG. 8A shows a first perspective view of the electronic device in theform of a tablet device and the accessory device in the form of aprotective cover.

FIG. 8B shows a second perspective view of the electronic device in theform of a tablet device and the accessory device in the form of aprotective cover.

FIG. 9A shows a closed configuration of the cooperating system formed bythe tablet device and protective cover shown in FIGS. 8A and 8B.

FIG. 9B shows an open configuration of the cooperating system shown inFIG. 9A.

FIG. 10A shows a top view of an embodiment of a segmented coverassembly.

FIG. 10B shows a representative magnetic assembly.

FIG. 11 shows representation of hinge assembly coupled to tablet deviceforming as part of a triangular support structure illustratingrepresentative magnetic interaction mechanisms.

FIGS. 12A-12D show representative cross sectional views of segmentedcover assembly/tablet device along line AA shown in FIG. 10A.

FIGS. 13A-13B show a side view of a segmented cover configured tosupport a tablet device in a keyboard state.

FIGS. 14A-14C show side and perspective views, respectively, of thesegmented cover configured to support a tablet device in a displaystate.

FIGS. 15A-15B shows cover assembly and tablet device in peek mode.

FIG. 16 shows an exploded view of segmented cover.

FIG. 17 is a block diagram of an arrangement of functional modulesutilized by a portable media device.

FIG. 18 is a block diagram of an electronic device suitable for use withthe described embodiments.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims.

The following description relates in general to a mechanism that can beused to attach together at least two suitably configured objects. In oneembodiment, this can be accomplished without the use of conventionalfasteners. Each of the objects can include an attachment featurearranged to provide a magnetic field having appropriate properties. Whenthe attachment features are brought into proximity with each other, themagnetic fields can cooperatively interact based upon their respectiveproperties, result in the objects magnetically attaching to each otherin a desired and repeatable manner. For example, due at least in part tothe cooperative nature of the interaction of the magnetic fields, theobjects can attach to each other in a pre-determined position andrelative orientation without external intervention. For example, thecooperative magnetic interaction can result in the objects self-aligningand self-centering in a desired orientation.

The objects can remain in the magnetically attached state if and until areleasing force of sufficient magnitude is applied that overcomes theoverall net attractive magnetic force. In some cases, however, it can bedesirable to detach the objects serially (along the lines of a zipper)in which case, the releasing force only need be of sufficient magnitudeto overcome the net magnetic attractive force of one pair of magneticelements at a time. Connectors such as mechanical fasteners are notrequired to attach the objects together. Furthermore, to prevent undueinterference to the magnetic interaction between the magnetic attachmentfeatures, at least a portion of the objects in the vicinity of themagnetic attachment features can be formed of magnetically inactivematerials such as plastic or non-ferrous metals such as aluminum ornon-magnetic stainless steel.

The objects can take many forms and perform many functions. Whenmagnetically attached to each other, the objects can communicate andinteract with each other to form a cooperative system. The cooperatingsystem can perform operations and provide functions that cannot beprovided by the separate objects individually. In another embodiment, atleast one device can be used as an accessory device. The accessorydevice can be magnetically attached to at least one electronic device.The accessory device can provide services and functions that can be usedto enhance the operability of the electronic device(s). For example, theaccessory device can take the form of a protective cover that can bemagnetically attached to the electronic device. The protective cover canprovide protection to certain aspects (such as a display) of theelectronic device while enhancing the overall look and feel of theelectronic device. The magnetic attachment mechanism used tomagnetically attach the accessory and the electronic device can assurethat the cover can only attach to the electronic device in a specificorientation. Moreover, the magnetic attachment mechanism can also assureproper alignment and positioning of the protective cover and theelectronic device.

The protective cover can include at least a flexible hinge portion. Theflexible hinge portion can include a flexible body, or tail, connectedto a magnetic attachment mechanism that can include a plurality ofmagnets. A magnetic field provided by the magnets in the magneticattachment mechanism can interact with a corresponding magnetic fieldprovided by magnets in the electronic device. In this way, the hingeportion can be pivotally connected to the electronic device using onlythe magnets. In one embodiment, the protective cover can include a flapthat is connected to the flexible hinge portion. The flap can thereforebe smoothly rotated along a pivot line formed by the flexible hingeportion. When magnetically coupled to the tablet device, the smoothrotation of the flap about the pivot line can bring the flap insubstantial contact with the display in a fully closed position. Theflap can also be smoothly rotated about the pivot line to reveal most orall of the display. In one embodiment, the flap can be segmented bywhich it is meant that the flap can be divided into distinct portionsthat can fold and bend with respect to each other as well as the tabletdevice more specifically in some cases, the display. In this way, thesegmented flap affords an additional option of revealing only specificportions of the display by folding individual segments to reveal acorresponding portion of the display while other segments remain incontact and therefore obscuring the display.

In some embodiments, the flap can include a variety of magnets that canbe used to form a number of structures well suited for use with theelectronic device. For example, the flap can include a first pluralityof magnets linearly arrayed along a first edge (i.e., first edgemagnets) and a second plurality of magnets positioned in correspondinglocations along a second edge opposite the first edge (second edgemagnets). In a particular embodiment, corresponding ones of the firstand second edge magnets have opposite polarities. In this way, when thefirst edge and the second edge are brought into spatial proximity toeach other, magnetic fields of the first and second edge magnetsinteract with each other to form a magnetic attractive force that causesthe first and second edges to attach to each other. In this way, theflap can form a structure that can be used to enhance the functionalityof the cover with regards to the electronic device.

For example, if the flap is constructed to have three independentlyfoldable segments (referred to as segment A, segment B, and segment C)where segment A is attached to the foldable hinge at the first edgehaving the first edge magnets and segment C is opposite segment A thatis defined in part by the second edge having the second edge magnets, atriangular structure ABC can be formed when the first edge magnets andthe second edge magnets attract each other when segment A is withinproximity to segment C. It should be noted that the properties of thetriangular structure ABC can vary in accordance with the relative sizesof the segments A, B, and C. In other words, is segments A, B, and C areabout equal in width, then triangular structure ABC can take the form ofan equilateral triangle, whereas if two segments are about of equalwidth, then the triangular structure ABC can take on the shape of anisosceles triangle. It should be noted that in some embodiments, thetriangular structure can be used to present the display at an angle ofabout 5-15° in a keyboard mode well suited for using a keyboardpresented at the display or about 65-80° in a movie mode well suited forviewing visual content presented at the display at a comfortable viewingangle.

In one embodiment, the flap can include electronic circuits or otherelements (passive or active) that can cooperate with electronic elementsin the electronic device. As part of that cooperation, signals can bepassed between the protective cover and the electronic device that can,for example, be used to modify operations of the electronic device,operations of electronic circuits or elements of the protective cover,and so forth. As an example, the electronic device can include one ormore magnetically sensitive circuits such as a Hall Effect sensor and assuch can detect the presence of a magnetic field. The Hall Effect sensorcan respond to properties of a magnetic field (such as the presence ofmagnetic field, a magnetic field strength, polarity, etc.) by generatinga signal. The signal can be used to alter an operating state of theelectronic device.

Accordingly, the protective cover can include a magnetic element, orelements, such as a permanent magnet having a magnetic field that can bedetected the Hall Effect sensor to generate the signal. The magnet(s)can be positioned in the protective cover in various locations in theflap that can be detected by the magnetic sensors when the magnets areproximate to the corresponding magnetic sensor. The magnetic sensors cansend information to a processor in the electronic device that canevaluate the signals from the multiple sensors. The evaluation of thesignals from the sensors can provide the processor with information thatcan be used to determine a spatial relationship between the flap and theelectronic device or even if the protective cover is attached to theelectronic device. For example, the processor can use the signals fromthe sensors to indicate a relative position of the flap to theelectronic device and in response alter an operating state of theelectronic device accordingly. For example, when the signals indicatethat the flap is fully closed (i.e.; both magnetic sensors detect acorresponding magnetic field), then the processor can prevent thedisplay from presenting visual content. On the other hand, if one sensordetects the corresponding magnetic field and the other sensor does notdetect the corresponding magnetic field, then the processor can use thisinformation to determine that only a portion of the display is viewable(that portion of the display corresponding to the portion of the flaphaving the magnet that is not detectable by the sensor). In thissituation, the processor can cause the display to present visual contentat only the viewable portion of the display.

These and other embodiments are discussed below with reference to FIGS.1-18. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanatory purposes only and should not be construed as limiting. Forthe remainder of this discussion, a first and second object eachsuitably configured to magnetically attach to each other in accordancewith the described embodiments will be described. It should be noted,however, that any number and type of suitably configured objects can bemagnetically attached to each other in a precise and repeatable manner.In particular, for simplicity and clarity, for the remainder of thisdiscussion, the first object is presumed to take the form of anelectronic device and in particular a handheld electronic device. Thehandheld electronic device can, in turn, take the form of a tabletdevice, portable media player, and so forth.

FIG. 1 is a simplified block diagram of article 10 and electronic device12 that can be releasably attached to each other in a desired andrepeatable manner. More specifically, article 10 and electronic device12 can attach to each other at a pre-determined position and relativeorientation without external intervention and without the use ofmechanical fasteners. Article 10 and electronic device 12 can remainattached to each other if and until a releasing force is applied thatovercomes the engagement between them. In some cases, however, it can bedesirable to detach article 10 and electronic device 12 serially (alongthe lines of a zipper) in which case, a releasing force can be appliedthat can undo the engagement between article 10 and electronic device 12about one attachment component at a time. For example, an attachmentcomponent can include a suitably matched pair of magnetic elements, onein article 10 and a second in electronic device 12.

Electronic device 12 can take many forms. For example, electronic device12 can take the form of a portable electronic device. In some examples,the portable electronic device can include housing 15. Housing 15 canenclose and provide support for components of the portable electronicdevice. Housing 15 can also provide support for at least a large andprominent display occupying a substantial portion of a front face of theportable electronic device. The display can be used to present visualcontent. The visual content can include still images, visual, textualdata, as well as graphical data that can include icons used as part of agraphical user interface, or GUI.

In some cases, at least a portion of the display can be touch sensitive.By touch sensitive it is meant that during a touch event, an object(such as a finger, stylus, and so on) can be placed in contact with orin proximity to an upper surface of the display. The particulars of thetouch event (location, pressure, duration, and so forth) can be used toprovide information to the portable electronic device for processing. Insome embodiments, in addition to or in place of information beingprovided to the portable electronic device, information can be providedby the portable electronic device in a tactile manner using, forexample, haptic actuators. It should be appreciated however that thisconfiguration is by way of example and not by way of limitation as theelectronic device can be widely varied. In one example, the portableelectronic device is a tablet device such as, for example, the iPad™manufactured by Apple Inc. of Cupertino, Calif.

Article 10 can be widely varied and can take many forms such as, forexample, an accessory or accoutrement of electronic device 12. As anaccessory, article 10 can be configured as a cover, a stand, a dock, ahanger, an input/output device and so on. In a particularly useful form,article 10 can take the form of a protective cover that can include amember, such as a flap, that can be positioned over the display of theportable electronic device. Like the electronic device 12, the article10 can also include housing 17 that can enclose and provide support forcomponents of the article 10.

Either one or both of article 10 and electronic device 12 can includeattachment features. For example, article 10 can include attachmentsystem 13 and electronic device 12 can include corresponding attachmentsystem 14. Attachment system 13 can cooperate with correspondingattachment system 14 to attach article 10 and electronic device 12 in areleasable manner. When attached to each other, article 10 andelectronic device 12 can operate as a single operating unit. On theother hand, in the detached mode, article 10 and electronic device 12can act separately, and if desired, as two individual parts. Attachmentsystems 13 and 14 can be configured in such a way that article 10 andelectronic device 12 can attach to each other in a desired andrepeatable manner. In other words, attachment systems 13 and 14 canrepeatedly align article 10 and electronic device 12 together such thatthey are consistently in a pre-determined position relative to oneanother.

The attachment features can be widely varied. The attachment can beprovided by various types of couplings including mechanical, electrical,static, magnetic, frictional, and/or the like. In one embodiment, theattachment cannot be seen from the outside of the article and/orelectronic device. For example, the article and device can not includeexternal visible attachment features that adversely affect the look andfeel or ornamental appearance (e.g., snaps, latches, etc.), but ratherattachment features that cannot be seen from the outside of the articleor device and thus do not affect the look and feel or ornamentalappearance of the article or device. By way of example, the attachmentfeatures can be provided by attraction surfaces that do not disturb theexternal surfaces of the article or device. In one embodiment, at leasta portion of the attachment features utilize magnetic attraction toprovide some or all of the attaching force.

The attachment systems can include one or more attachment features. Ifmultiple features are used, the manner in which they secure can be thesame or different. For example, in one implementation, a firstattachment feature utilizes a first attachment mechanism while a secondattachment feature utilizes a second attachment mechanism that isdifferent than the first attachment mechanism. For example, the firstattachment mechanism can utilize a friction coupling while the secondattachment means can utilize magnetism. For example, the first andsecond attachment mechanisms can be provided by magnets. Although, theattachment mechanisms can be similar it should be appreciated that theconfiguration of the mechanisms can be different depending on the needsof the system. Further, any number and configuration of attachmentmechanisms can be used.

In the illustrated embodiment, the attachment systems 13 and 14 eachinclude at least a first set of corresponding attachment features 13a/14 a and a second set of corresponding attachment features 13 b/14 b.Attachment feature 13 a can cooperate with corresponding attachmentfeature 14 a to attach article 10 and electronic device in a releasablemanner. In one particular implementation this is accomplished withmagnetic attraction. Further, attachment feature 13 b can cooperate withcorresponding attachment feature 14 b to further attach article 10 andelectronic device in a releasable manner. In one particularimplementation this is accomplished with magnetic attraction. By way ofexample, attachment features 13 a/14 a can be provided at a firstlocation while attachment features 13 b/14 b can be provided at a secondlocation.

In a specific example, attachment feature 14 a can, in cooperation withattachment feature 13 a, secure electronic device 12 to article 10. Inanother example, attachment feature 13 b can secure article 10 to theelectronic device 12 using attachment feature 14 b. It should be notedthat the attachment systems 13 and 14 of this example can be separate orthey can cooperate together to produce the attachment. If theycooperate, attachment features 14 a and 14 b correspond to or mate withone or more attachment features 13 a and 13 b. In any case, theattachment features in any of these examples can be accomplished throughmechanical, static, suction, magnetic attachment and/or the like.

The placement of the attachment systems and the attachment featureswithin the attachment systems can be widely varied. Regarding electronicdevice 12, attachment system 14 can be placed on front, back, top,bottom, and/or sides. Attachment features 14 a and 14 b can be placedany location within attachment system 14. Accordingly, attachmentfeatures 14 a and 14 b can be placed anywhere relative to the housingand/or the display. In one example, the attachment features 14 a and 14b can provide engagement along one or more of the sides of the housing(e.g., top, bottom, left, right). In another example, attachmentfeatures 14 a and 14 b can provide engagement at the back of electronicdevice 12. In yet another example, attachment features 14 a and 14 b canprovide engagement at the front (e.g., where, if present, a display islocated) of electronic device 12. In some cases, a combination ofattachment features can be located at different regions of electronicdevice 12 as for example at the sides and front. In one embodiment,attachment system 14 including attachment features 14 a and 14 b do notdisturb the surfaces of electronic device 12. Similarly, attachmentsystem 13 and in particular attachment features 13 a and 13 b do notdisturb the surfaces of article 10.

In accordance with one embodiment, the attachment features can includemagnetic elements. The magnetic elements can be configured to help inpositioning article 10 relative to electronic device 12 into a matingarrangement. The magnetic elements can further help to secure article 10and electronic device 12 into a mating engagement. It should be notedthat the engagement of article 10 and electronic device 12 can bereversed by the application of an appropriate releasing force thatallows article 10 and electronic device 12 to separate back intoindividual objects. However, the magnetic elements can permit thearticle 10 and electronic device 12 to subsequently resume the matingengagement without the requirement of fasteners of any sort, mechanicalor otherwise. In this way, the magnetic elements provide a repeatableand consistent engagement between article 10 and electronic device 12.

Article 10 and electronic device 12 can further include components 16and 18 respectively. Components 16 and 18 typically depend on theconfiguration of article 10 and electronic device 12 and can, forexample, be mechanical or structural components used to provide supportor they can be operational/functional components that can provide aspecific set of operations/functions. The components can be dedicated totheir respective devices or they may be configured for coupling withaspects of the corresponding article or device (e.g., wired orwireless). Examples of structural components can include frames, walls,fasteners, stiffeners, movement mechanisms (hinge), etc. Examples ofoperational components can include processors, memory, batteries,antennas, circuitry, sensors, display, inputs, and so on. Depending ontheir desired configuration, the components can be external (i.e.,exposed at the surface) and/or internal (e.g., embedded within housing).

FIGS. 2A and 2B are simplified perspective views of article 20 that canbe releasably attached to electronic device 22 via a magnetic attachmentsystem, in accordance with one described embodiment. Article 20 andelectronic device 22 can generally correspond to those discussed withregards to FIG. 1. In one embodiment, the magnetic attachment system canbe embodied as magnetic surface 24 (shown by broken lines or shading)and more particularly as magnetic surface 24 at the sides of electronicdevice 22. Magnetic surface 24 can provide a magnetic field that cancooperate with a corresponding attachment feature in article 20 whenplaced in proximity to one another. The magnetic field can establish anet magnetic attractive force that can pull article 20 and electronicdevice 22 together into the mating engagement along engagement surface26 as shown in FIG. 2B.

In other words, the magnetic field provided by magnetic surface 24 canhave properties such that the net magnetic attractive force betweenarticle 20 and electronic device 22 is substantially perpendicular toengagement surface 26. Moreover, the magnetic field can result in thenet magnetic attractive force between article 20 and electronic device22 being applied uniformly along engagement surface 26. In order torelease article 20 and electronic device 22, a releasing force can beapplied to the two conjoined objects in order to overcome a net magneticattractive force provided by the magnetic attachment system.

It also should be appreciated that although only one side wall is shown,in some cases different sidewalls and possibly a combination ofsidewalls may be used depending on the needs of the attachmentinterface. It should be noted that the use of magnetic attachmentprecludes the need for mechanical attachments such as fasteners.Moreover, the lack of mechanical attachments and the uniformity of theoverall magnetic attractive force can leave the surfaces of article 20and electronic device 22 undisturbed helping to create an appearance ofoneness by in which article 20 and electronic device 22 can appear as asingle, unified entity. The uniformity in appearance can improve theoverall aesthetic appeal of both article 20 and electronic device 22.

In one embodiment, a magnetic surface can be created by embeddingmagnetically attractable elements in the form of the magnetic attachmentfeature within the sidewalls of electronic device 22 and/or article 20.That is, the magnetically attractable elements can be disposed withinarticle 20 and electronic device 22 as for example within the housing ofelectronic device 22. In this configuration, the housing can be formedof non-magnetic material such as plastic or non-ferrous metal such asaluminum. In this way, magnetic force lines can be configured to workthrough the walls of the housing. The magnetic attachment features donot disturb the physical appearance of the external surfaces of article20 and electronic device 22. The magnetically attractable elements inarticle 20 and electronic device 22 can be arranged to produce magneticfields that can cooperate with each other to generate a magneticattractive force that attaches article 20 and electronic device 22together in the mating engagement. The magnetic attractive force beingconfigured to generate a magnetic attraction force normal to engagementsurface 26 between electronic device 22 and article 20.

The magnetic attractive force between corresponding magnetic elements inarticle 20 and electronic device 22 can also be uniformly applied alongengagement surface 26. The uniformity of the overall magnetic attractiveforce along engagement surface 26 can be a result of the uniformity ofthe separation distance between corresponding magnetic elements inarticle 20 and electronic device 22. The uniformity can also be a resultof the consistency of magnetic flux density between correspondingmagnetic elements in article 20 and electronic device 22. The uniformityof net magnetic attachment can be facilitated by the surfaces of article20 and electronic device 22 each forming a well matched fit to eachother. For example, one surface can be flat or have a concave geometrywhereas the other surface can have a matching conforming convexgeometry. In this way, by fitting tightly together, a separationdistance between each of the corresponding magnetic elements in article20 and electronic device 22 can be reduced to a minimum. The conformityof surface shapes can also enhance the overall look and feel of article20 and electronic device 22 by reducing or eliminating the appearance ofa seam at engagement surface 26. This seamless quality can provide anillusion of a single entity when article 20 and electronic device 22 areattached to each other.

In addition to enhancing the overall look and feel, the consistency ofthe separation distance between the magnetic elements can render theattachment force between article 20 and electronic device 22 uniformalong engagement surface 26. In this way, the engagement force can beuniformly distributed across engagement surface 26 preventing buckling,weak spots, and so on that might otherwise affect the overall integrityof the engagement between article 20 and electronic device 22.

FIGS. 3A and 3B are simplified perspective views of article 30 that canbe releasably attached to an electronic device 32 via magneticattachment system 34 and corresponding attachment system 36. It shouldbe noted that this particular embodiment is similar to the embodimentdescribed in FIGS. 2A, 2B except that the magnetic surfaces that werepreviously located at the side walls are now located on a face ofelectronic device 32 and, optionally, an opposing face on article 30.For example, in the case of an electronic device including a display,the magnetic elements of magnetic attachment system 34 can be embeddedbehind the display surface.

FIG. 3B shows article 30 and electronic device 32 magnetically attachedto each to each other to form cooperating system 38. As part of system38, electronic device 32 and article 30 can cooperate with each other toprovide features not available by article 30 or electronic device 32separately. For example, article 30 can take the form of a cover thatcan provide protective features. In one embodiment, protective cover canbe used to support and protect electronic device 32 while beingtransported or stored (e.g., cover the display surface). Due to thereleasable nature of the magnetic attachment between magnetic attachmentsystems 34 and 36, article 30 can be easily detached when electronicdevice 32 is to be used and subsequently re-attached when desired.

The placement of the magnetic elements can be such that only certainmagnetically sensitive elements within electronic device 32 are affectedby the magnetic field generated by the embedded magnetic elements. Forexample, a Hall Effect sensor can be used to detect whether or notarticle 30 is magnetically attached to and covering all or a portion ofthe display of electronic device 32 using the magnetic field generatedby a magnetic element located in article 30. On the other hand, amagnetically sensitive element in electronic device 32 such as a compassthat relies upon an external magnetic field (i.e., such as that providedby the Earth), must not be unduly affected by magnetic field linesgenerated by the embedded magnetic elements. Therefore, the magneticelements can be limited to those locations in electronic device 32positioned away from magnetically sensitive elements such as thecompass.

FIGS. 4A and 4C are simplified perspective views of article 40 that canbe releasably attached to electronic device 42 via a magnetic system 44.This embodiment is similar to that shown in FIGS. 2A, 2B and 3A, 3B inthat magnetic system 44 can include multiple magnetically attractableelements and that article 40 and electronic device 42 generallycorrespond to those mentioned in previous Figures. For example, one setof magnetically attractable magnetic elements 44 a can be placedrelative to a side of article 40 and electronic device 42 while a secondset of magnetically attractable elements 44 b can be placed relative toa face of article 40 and electronic device 42. As shown in FIG. 4B,cooperating system 46 can be formed by placing article 40 and electronicdevice 42 within proximity to each other such that magnetic elements 44a on the sides of article 40 and electronic device 42 magneticallyattract each other in addition to magnetic elements 44 b located at theface of electronic device 42 and article 40. The overall magneticattraction generated at the side and face can be sufficient to retainarticle 40 and electronic device 42 in a mating engagement to formcooperating system 46.

In one embodiment, as shown in FIG. 4C, cooperating system 46 ispresented in an open configuration in which article 40 is used as acover for electronic device 42 that can be opened and closed. That is,article 40 can act as a protective cover of electronic device 42. Inthis embodiment, article 40 can include binding 48 that attaches alongthe side of electronic device 42 and flap 50 that attaches to the frontface of electronic device 42 and more particularly, top face 52. Topface 52 can correspond to a display. In one implementation, flap 50 canmove relative to binding 48. The moving can be widely varied. In oneexample, flap 50 can pivot relative to binding 48. The pivot can bewidely varied. In one example, the pivot can be enabled by a hingemechanism. In another example, the pivot can be enabled by a fold.Furthermore, the flap can be rigid, semi-rigid or flexible. In thismanner, article 40 can form an open configuration where flap 50 ispositioned away from electronic device 42 (display 52 can be viewed) anda closed configuration where flap 50 is positioned adjacent electronicdevice 42 (display 52 is covered as represented by closed embodiment ofFIG. 4B). In one embodiment, binding 48 is only located on one sidewhile flap 50 is only located at top face 52. In so doing, the othersurfaces of electronic device 42 are left exposed. As a result, thebeauty of the electronic device may be shown off while the article isattached to the electronic device. Further, it may leave better accessfor I/O and connectivity related functionality (e.g., buttons,connectors, etc.).

Although the purpose of the magnetic elements is similar, i.e., attacharticle to electronic device, it should be appreciated that thesemechanisms can widely vary. In some cases, the magnetic fields may beconfigured differently. By way of example, the side mounted magneticsurface may provide a first magnetic force and the front facing magneticsurface may provide a second magnetic force that is different than thefirst magnetic force. This may be in part due to different holdingrequirements as well as different surface areas, i.e., available space,and its effect on internal components of the electronic device. In oneexample, the side mounted magnetic surface provides a greater holdingforce for securing the article to the electronic device, i.e., it is theprimary securing force while the front facing magnetic surface is thesecondary securing force.

In one example, flap 50 includes multiple sections that are semi-rigidand bend relative to one another so as to make the flap movable andflexible. In one embodiment, flap 50 can be folded into one or moredifferent configurations, and in some cases can be held in theseconfigurations using a magnetic system similar to what is describedabove. These and other embodiments will be described in greater detailbelow. Moreover, it should be appreciated that the described embodimentsare not limited to covers and that other configurations can be usedincluding for example as an accessory device used as a hangingapparatus, as a support mechanism for the electronic device to improveviewing the display and as a support mechanism for or inputting touchevents at a touch sensitive portion of the display, and so on.

The electronic device and article can take many forms. For the remainderof this discussion, the electronic device is described in terms of ahandheld portable computing device. Accordingly, FIG. 5 shows a topperspective view of electronic device 100 in accordance with thedescribed embodiments. Electronic device 100 can process data and moreparticularly media data such as audio, visual, images, etc. By way ofexample, electronic device 100 can generally correspond to a device thatcan perform as a smart phone, a music player, a game player, a visualplayer, a personal digital assistant (PDA), a tablet device and thelike. Electronic device 100 can also be hand held. With regards to beinghandheld, electronic device 100 can be held in one hand while beingoperated by the other hand (i.e., no reference surface such as a desktopis needed). Hence, electronic device 100 can be held in one hand whileoperational input commands can be provided by the other hand. Theoperational input commands can include operating a volume switch, a holdswitch, or by providing inputs to a touch sensitive surface such as atouch sensitive display device or a touch pad.

Electronic device 100 can include housing 102. In some embodiments,housing 102 can take the form of a single piece housing formed of anynumber of materials such as plastic or non-magnetic metal which can beforged, molded, or otherwise formed into a desired shape. In those caseswhere electronic device 100 has a metal housing and incorporates radiofrequency (RF) based functionality, a portion of housing 102 can includeradio transparent materials such as ceramic, or plastic. Housing 102 canbe configured to enclose a number of internal components. For example,housing 102 can enclose and support various structural and electricalcomponents (including integrated circuit chips) to provide computingoperations for electronic device 100. The integrated circuits can takethe form of chips, chip sets, or modules any of which can be surfacemounted to a printed circuit board, or PCB, or other support structure.For example, a main logic board (MLB) can have integrated circuitsmounted thereon that can include at least a microprocessor,semi-conductor memory (such as FLASH), and various support circuits andso on. Housing 102 can include opening 104 for placing internalcomponents and as necessary can be sized to accommodate display assemblyfor presenting visual content, the display assembly being covered andprotected by protective layer 106. In some cases, the display assemblycan be touch sensitive allowing tactile inputs that can be used toprovide control signals to electronic device 100. In some cases, thedisplay assembly may be a large prominent display area that covers amajority of the real estate on the front of the electronic device.

Electronic device 100 can include a magnetic attachment system that canbe used to magnetically attach electronic device 100 to at least oneother suitably configured object. The magnetic attachment system caninclude a number of magnetic attachment features distributed within andin some cases connected to housing 102. For example, the magneticattachment system can include first magnetic attachment feature 108 andsecond magnetic attachment feature 110 located on different sides ofelectronic device 100. In particular, first magnetic attachment feature108 can be located in proximity to side wall 102 a of housing 102.Second magnetic attachment feature 110 can be located within opening 104near side walls 102 c and 102 d proximate to side wall 102 b of housing102. By placing magnetic attachment feature 110 at opposite side walls,an amount of racking (or lateral movement) of a cover magneticallysecured by attachment feature 110 can be substantially reduced. In thoseembodiments where electronic device 100 includes a display with coverglass 106 substantially filling opening 104, second attachment feature110 (also referred to as securing attachment feature 110) can be placedbeneath cover glass 106. It should be noted that without loss ofgenerality, first magnetic attachment feature 108 will henceforth bereferred to as device attachment feature 108.

Although not expressly shown, it is understood that the various magneticattachment features of the magnetic attachment system can be located atany appropriate location of housing 102. For example, magneticattachment features can be located at an interior bottom surface ofhousing 102 or along sides 102 c and 102 d of housing 102.

As shown in FIG. 6, device attachment feature 108 and securingattachment feature 110 can each include one or more magnetic elements.In one example, device attachment feature 108 can multiple magneticelements that can magnetically interact with each other to providemagnetic field 112 (only a portion of which is shown). In other words,the properties (shape, field strength, and so on) of magnetic field 112can be based upon the interaction of the magnetic fields generated byeach of the magnetic elements. In this way, the properties of magneticfield 112 can be altered simply by arranging the properties (i.e.,physical layout, relative size, and constituent magnetic polarities) ofeach of the magnetic elements. For example, each of the magneticelements can have varying sizes and can be disposed along an axis. Inthis way, the magnetic properties of each of the plurality of magneticelements can act together to establish the overall properties ofmagnetic field 112.

In some cases, the portion of magnetic field 112 that is used in themagnetic attachment between device attachment feature 108 and anotherdevice can be enhanced with the use of a magnetic shunt (not shown). Themagnetic shunt can be formed of magnetically active material, such assteel or iron, and be placed in a position that causes magnetic fieldlines that would otherwise be directed away from the attachment regionto be at least partially re-directed towards the attachment region. There-direction of the magnetic field lines can have the effect ofincreasing the average magnetic flux density in the attachment region.

Device attachment feature 108 can operate in an active state as in wellas an inactive state. Magnetic flux density B₁₁₂ can equal or exceed amagnetic flux density threshold B_(threshold) inside the exteriorsurface of housing 102 but not outside in the inactive state. In otherwords, magnetic flux density B₁₁₂ of magnetic field 112 at an exteriorsurface of housing 102 is less than a magnetic flux density thresholdB_(threshold). Magnetic flux density threshold B_(threshold)representing a magnetic flux value below which magnetically sensitivedevices (such a magnetic strip on a credit card) can remainsubstantially unaffected. In addition, the presence of a magneticallyactive material (such as steel) in the region outside of electronicdevice 100 will not by itself trigger device attachment feature 108 totransition from the inactive state to the active state.

The properties of magnetic field 112 can include at least fieldstrength, magnetic polarity, and so on. The properties of magnetic field112 can be based upon the combination of the magnetic fields from eachof the magnetic elements included in magnetic attachment feature 108 Thecombined magnetic fields can form in the aggregate magnetic field 112.For example, the magnetic elements can be arranged in such a way thatthe combination of the respective magnetic fields results in magneticfield 112 having desirable magnetic field properties (such as fieldstrength). For example, the combination of one arrangement of magneticelements can result in magnetic field 112 having characteristics (such apolarity and strength) that are for the most part symmetric about aparticular axis (such as a geometric center line).

On the other hand, the magnetic elements can be arranged in such a waythat the combination of the magnetic fields of the magnetic elements canresult in magnetic field 112 having at least one property that isanti-symmetric about the center line. For example, a magnetic element onone side of the centerline can be positioned with a North magnetic polepointing up whereas a corresponding magnetic element on the other sideof the centerline can be arranged with a South magnetic pole pointingup. Hence, the magnetic properties of magnetic field 112 can be adjustedin any manner deemed appropriate to provide a desired mating engagement.For example, the magnetic properties of magnetic field 112 can bemodified by arranging the magnetic elements in such a way that magneticfield 112 can cooperatively interact with another magnetic field (fromanother magnetic attachment system, for example). The cooperativeinteraction between the two magnetic fields can result in the twoobjects being magnetically attached to each other in a well-defined,precise, and repeatable manner.

The properties of magnetic field 112 can be stable. By stable it ismeant that the properties of the magnetic field can remain essentiallyunchanged for an extended period of time. Hence, a stable version ofmagnetic field 112 can be created using magnetic elements havingproperties that are essentially constant (or nearly constant) over anextended period of time or at least any changes in one component isoffset by a corresponding change in another component. The magneticelements can be physically arranged in a fixed or at least substantiallyfixed configuration with respect other magnetic elements. For example,the magnetic elements can each have fixed sizes and polarities arrangedin a specific order relative to each other providing the desiredproperties (shape, strength, polarity, etc.) of magnetic field 112.Hence, depending upon the properties and the nature of the magneticelements, the shape of magnetic field 112 can remain substantiallyunchanged over the extended period of time (such as the anticipatedoperating life of electronic device 100).

In some embodiments, however, the properties of magnetic field 112 canbe varied by modifying a magnetic or other physical property of at leastone of the magnetic elements. When at least one magnetic element hasmagnetic properties (e.g., a polarity or field strength) that can bemodified, the resulting magnetic field can also be modified.Accordingly, in some embodiments at least one of the magnetic elementscan be characterized as having dynamic magnetic properties. By dynamicit is meant that at least one magnetic property, such as polarity, canbe modified. In this way, the magnetic field properties of the resultingmagnetic field can also vary. The resulting magnetic field, in turn, canalter the magnetic characteristics of magnetic field 112 that, in turn,can alter how the magnetic attachment system causes the objects tomagnetically attach to each other (alignment, orientation, centering,and so forth). An electromagnet is one example of such a magneticelement whose magnetic properties can be modified as desired. Otherexamples include a malleable non-magnetic substrate impregnated withmagnetic dopant (such as magnetite). In this way, the malleablesubstrate can be formed into a physical shape that can affect the natureof the magnetic field produced by the magnetic dopant material.

Turning now to other aspects of the magnetic attachment system, securingattachment feature 110 can include one or more of magnetic elements 116.When a plurality of magnetic elements is used, the arrangement of theplurality of magnetic elements 116 can be widely varied and canmagnetically interact with a cooperating feature on another device. Inone embodiment, the plurality of magnetic elements 116 associated withsecuring feature 110 can assist in securing at least a portion ofanother device otherwise attached to electronic device 100 by way ofdevice attachment feature 108.

At least some of the plurality of magnetic elements 116 can have a fixedsize and polarity (along the lines of a simple bar magnet) whereas otherof the plurality of magnetic elements 116 can have magnetic propertiesthat can vary (such as an electromagnet) while still others can beshaped to provide specific magnetic characteristics. For example, atleast one of the plurality of magnetic elements 116 can be positionedand shaped (if need be) to interact with a magnetically responsivecircuit included in the other device. Hence, the magnetically responsivecircuit can respond to the presence (or absence) of a particularmagnetic element(s) of securing feature 110. An example of themagnetically responsive circuit is described above with regards to theHall Effect sensor(s) 118.

It should be noted that the magnetic field generated by magneticelements 116 should not extend so far that magnetically sensitivecircuits within electronic device 100 (such as Hall Effect sensors 118)are adversely affected. This is particularly important since themagnetic field is not generally contained within housing 102 since atleast a portion of the magnetic field must extend in the z direction inorder to interact with the magnetically active portion of other devices.Therefore, the magnetic field in {x,y} must be limited in extent toavoid magnetically sensitive circuits such as Hall Effect sensor 118 andcompass 120. In one embodiment, the shaping of the magnetic field in{x,y} can be accomplished using what can be referred to as shapingmagnets discussed in more detail below. Moreover, some or all of magnets116 can be shaped (such as a trapezoid) that contours magnetic fieldlines between each of the magnets 116 to restrict the extent in {x,y} toavoid unduly affecting sensitive magnetic circuits such as compass 120.

In a particular implementation, the magnetic elements of deviceattachment feature 108 can be grouped into distinct magnetic regions. Inthis way, the magnetic fields from the magnetic regions can superpose toform magnetic field 112. The magnetic regions can include variousmagnetic elements that can be arranged into groups represented bymagnetic elements 126 and 128. By grouping the magnetic element intoseparate magnetic regions, the ability of the magnetic attachment systemto provide a magnetic field having desired characteristics can besubstantially enhanced. Magnetic elements 126 and 128 can interact witheach other to form magnetic field 112. In the one embodiment, theinteraction can take the form of combination of magnetic properties ofeach of magnetic elements 126 and 128. In some cases, the arrangement ofmagnetic elements 126 and 128 can be related to each other in order toprovide magnetic field 112 with desired characteristics. For example,magnetic elements 126 can 128 can be arranged in such a way relative toone another that magnetic field 112 is anti-symmetric (or symmetric)about a horizontal center line of magnetic attachment feature 108. Inanother embodiment, magnetic field 112 can be anti-symmetric (orsymmetric) about a vertical center line of attachment feature 108. Instill another embodiment, magnetic field 112 can be anti-symmetric (orsymmetric) both horizontally and vertically.

FIG. 7A shows electronic device 100 in proximity to object 200 havingmagnetic attachment feature 202. Magnetic attachment feature 202 ofobject 200 can include magnetic elements each generating an individualmagnetic field that can interact with the other to form in the aggregatea resulting magnetic field. The resulting magnetic field can havemagnetic characteristics (such as field strength and shape) that caninteract with magnetic field 112 of electronic device 100 to attachelectronic device 100 and object 200 together in a well-defined,precise, and repeatable manner without mechanical fasteners and norrequire external assistance. Object 200 can take many forms including anaccessory, peripheral, electronic device or the like. In one embodiment,object 200 can take the form of an electronic device along the lines ofelectronic device 100. Accordingly, electronic device 100 and electronicdevice 200 can be magnetically attached to each other using deviceattachment feature 108 and magnetic attachment feature 202 to form acooperative electronic system. The cooperative electronic system can beone in which electronic elements in electronic device 100 andcorresponding electronic elements in electronic device 200 cooperatewith the other to perform functions that cannot be performed by eitherof the electronic devices separately. In one embodiment, information canbe passed between electronic devices 100 and 200.

More specifically, magnetic attachment feature 202 can include at leastmagnetic elements 204 and 206 each of which can generate magnetic fieldsthat cooperate with each other to provide magnetic field 208 (only aportion of which is shown). The properties of magnetic field 208 can bebased upon the interaction of each of the plurality of magnetic elements204 and 206. In this way, magnetic field 208 can have properties basedupon the physical layout, relative size, and constituent magneticpolarities of each of the plurality of magnetic elements 204 and 206.For example, magnetic elements 204 and 206 can be disposed along acenter line and have magnetic properties that superpose to providemagnetic field 208 with desired properties.

In addition to magnetic attachment feature 202, accessory device 200 canfurther include magnetic attachment feature 216 that can be used tointeract with securing attachment feature 110. Magnetic attachmentfeature 216 can include a variety of magnetically active components.Some of the magnetic elements can take the form of magnetic elementsarranged to cooperatively interact with corresponding magnetic elementsin securing attachment feature 110. Other of the magnetic element can bemore passive in nature in that they provide a mechanism for completing amagnetic circuit with magnetically active elements in securingattachment feature 110. An example of a magnetically passive element isa ferromagnetic material, such as iron or steel, that can be interactwith a magnetic element actively providing an associated magnetic field.In this way, the ferromagnetic material can interact with the magneticfield to complete a magnetic circuit between the passive element inattachment feature 216 and the active element in securing attachmentfeature 110.

As shown in FIG. 7B, the overall magnetic attractive force F_(NET)between device 100 and device 200 at engagement surface 218 can bederived as the summation of all the net magnetic attractive forcesF_(neti) for all actively coupled magnetic elements. In other words, theoverall net magnetic attractive force F_(NET) satisfies the followingequation:

F_(NET)=Σ₁ ^(n)F_(neti)

where F_(neti) is the net magnetic attractive force for each of ncomponents. In one embodiment, net magnetic attractive force F_(neti) issubstantially perpendicular to that portion of engagement surface 218intersected by magnetic field 112 and magnetic field 208.

In order to assure that overall magnetic attachment force F_(NET) isuniform along the engagement surface between device 100 and device 200,the separation distances between each corresponding magnetic element inattachment features 108 and 202 are well controlled. The separationdistance can be well controlled by, for example, shaping the magneticelements to conform to the shape of the devices. For example, if device100 has a spline (curved) shaped housing, the magnetic elements indevice 100 can be shaped to conform to the curved shape. In addition,the magnetic elements can be formed in such a way that the magneticvectors of corresponding magnetic elements align with each other. Inthis way, the magnitude and direction of the net magnetic attractiveforce can be controlled as desired.

One result of the aligning of the magnetic vectors is that the directionof the net magnetic force between each magnetic element can be wellcontrolled. Moreover, by reducing the separation distance betweencorresponding magnetic elements to a minimum, the net attractivemagnetic force F_(neti) between each magnetic element can be maximized.In addition, maintaining a substantially uniform separation distancebetween the various magnetic elements, a correspondingly uniformmagnetic attachment force can be provided along engagement surface 218.Moreover, by appropriately adjusting the corresponding magnetic vectors,F_(net) can be applied normally to the engagement surface.

In addition to minimizing the separation distance between correspondingmagnetic elements, the magnetic flux density between the correspondingmagnetic elements can be increased by using magnetic shunts. A magneticshunt formed of magnetically active material such as iron or steel canbe placed on or near a magnetic element having the effect of directingmagnetic flux lines in a desired direction. In this way, for example,magnetic flux lines that would otherwise propagate in a direction awayfrom a corresponding magnetic element can be partially re-directedtowards a desired direction, such as towards a magnetic attachmentregion between the devices thereby increasing the overall magnetic fluxdensity. Hence, increasing the available magnetic flux density betweenthe magnetic elements can result in a substantial increase in the netmagnetic attractive force.

For the remainder of this discussion, various embodiments of accessorydevice 200 are discussed.

In one embodiment, accessory device 200 can include a number ofprotective elements that can be used to protect certain aspects ofelectronic device 100. For example, accessory device 200 can take theform of a protective cover. The protective cover can include a flappivotally connected to a hinge assembly. The hinge assembly can, inturn, be coupled to electronic device 100 by way of accessory attachmentfeature 202. In this way, the flap portion can be used as a protectivecover to protect aspects of electronic device 100 such as a display. Theflap can be formed of various materials such as plastic, cloth, leather,and so forth. The flap can be segmented in such a way that a segment ofthe flap can be lifted to expose a corresponding portion of the display.The flap can also include a functional element that can cooperate with acorresponding functional element in electronic device 100. In this way,manipulating the flap can result in an alteration in the operation ofelectronic device 100.

The flap can include magnetic material that can be used to activate amagnetically sensitive circuit in electronic device 100 based upon, forexample, the Hall Effect. The magnetically sensitive circuit can respondby generating a signal that can, in turn, be used to alter an operatingstate of electronic device 100. Since the cover can be easily attacheddirectly to the housing of the tablet device without fasteners, thecover can essentially conform to the shape of electronic device 100. Inthis way, the cover will not detract or otherwise obscure the look andfeel of electronic device 100.

Accessory device 200 can take the form of a support that can be used toenhance the functionality of electronic device 100. For example,accessory device 200 can be configured to act as a display stand onwhich a display of electronic device 100 can be viewed at a comfortableviewing angle such as 60°-85°. In other words, when placed upon ahorizontal surface such as a table or desk, accessory device 200 cansupport electronic device 100 in such a way that the visual contentpresented at the display can be viewed at about a viewing angle ofapproximately 60°-85°. Accessory device 200 can also take the form of asupport that can be used to enhance the functionality of electronicdevice 100 in a keyboard mode. In the keyboard mode, accessory device200 can be used to present a touch pad surface at an angle that isergonomically friendly. In this way, input touch events can be applied(to a virtual keyboard, for example) at an angle that does not overtax auser's wrist, hands, arms, etc.

The remainder of this discussion will describe particular embodiments ofdevices that can use the magnetic attachment system. In particular, FIG.8A and FIG. 8B show electronic device 100 presented in terms of tabletdevice 800 and accessory device 200 is shown as cover assembly 900 eachin perspective top views. These elements may generally correspond to anyof those previously mentioned. In particular, FIGS. 8A and 8B shows twoperspective views of tablet device 800 and cover assembly 900. Forexample, FIG. 8A shows magnetic surface 801 provided by deviceattachment feature 108 included in tablet device 800. In thisconfiguration, magnetic surface 801 does not exhibit sufficientintensity to adversely affect sensitive magnetic components in theproximity of tablet device 800. Therefore, in this inactive mode,magnetic field 112 associated with magnetic surface 801 does not exceedB_(threshold). FIG. 8B, on the other hand, is the view presented in FIG.8A rotated about 180° to provide a second view of attachment feature 904and its relationship with cover assembly 900.

As shown in FIG. 8A, tablet device 800 can include housing 802 that canenclose and support device attachment feature 108. In order to notinterfere with the magnetic field generated by device attachment feature108, at least that portion of housing 802 nearest device attachmentfeature 108 can be formed of any number of non-magnetic materials suchas plastic or non-magnetic metal such as aluminum. Housing 802 can alsoenclose and support internally various structural and electricalcomponents (including integrated circuit chips and other circuitry) toprovide computing operations for tablet device 800. Housing 802 caninclude opening 804 for placing internal components and can be sized toaccommodate a display assembly or system suitable for providing a userwith at least visual content as for example via a display. In somecases, the display assembly can include touch sensitive capabilitiesproviding the user with the ability to provide tactile inputs to tabletdevice 800 using touch inputs. The display assembly can be formed of anumber of layers including a topmost layer taking the form oftransparent cover glass 806 formed of polycarbonate or other appropriateplastic or highly polished glass.

Although not shown, the display assembly underlying cover glass 806 canbe used to display images using any suitable display technology, such asLCD, LED, OLED, electronic or e-inks, and so on. The display assemblycan be placed and secured within the cavity using a variety ofmechanisms. In one embodiment, the display assembly is snapped into thecavity. It can be placed flush with the adjacent portion of the housing.In this way, the display can present visual content that can includevideo, still images, as well as icons such as graphical user interface(GUI) that can provide information the user (e.g., text, objects,graphics) as well as receive user provided inputs. In some cases,displayed icons can be moved by a user to a more convenient location onthe display. In some embodiments, a display mask can be applied to, orincorporated within or under cover glass 806. The display mask can beused to accent an unmasked portion of the display used to present visualcontent and can be used to make less obvious device attachment feature108 and securing attachment feature 110. Cover 900 can include flap 902and (not shown) flexible hinge 904 that can magnetically interact withmagnetic attachment feature 108 to form a magnetic attachment forcesuitable for magnetically attaching cover 900 and tablet device 800.FIG. 8B shows tablet device 800 and cover 900 rotated in such a way toshow more clearly flexible hinge assembly 904.

Cover assembly 900 is shown in FIGS. 9A and 9B attached to tablet device800. FIG. 9A shows cover assembly 900 attached to tablet device 800 in afully closed configuration in which flap 902 fully covers cover glass806 and the corresponding portion of the display assembly. On the otherhand, FIG. 9B shows cover assembly 900 attached to tablet device 800 inan open configuration in which cover glass 806 is fully viewable. In oneembodiment, flap 902 can have a size and shape in accordance with a topportion of tablet device 800 such as cover glass 806. Flap 902 can bepivotally connected to flexible hinge assembly 904. Flexible hingeassembly 904 can include magnetic attachment feature 202 in the form ofan array of magnets arranged to magnetically interact with magneticfield 112 provided by magnetic attachment feature 108. The magneticattachment force between flexible hinge assembly 904 and attachmentfeature 108 can maintain cover assembly 900 and tablet device 800 in aproper orientation and placement vis-a-vis flap 902 and cover glass 806.By proper orientation it is meant that cover assembly 900 can onlyproperly attach to tablet device 800 having flap 902 and cover glass 806aligned in a mating engagement. The mating arrangement between coverglass 806 and flap 902 is such that flap 902 covers substantially all ofcover glass 806 when flap 902 is placed in contact with cover glass 806.

In order to transition from the closed to the open configuration,releasing force F_(release) can be applied to flap 902. Releasing forceF_(release) can overcome the magnetic attractive force betweenattachment feature 216 in flap 902 and attachment feature 110 in tabletdevice 800. Hence, cover assembly 900 can be secured to tablet device800 until releasing force F_(release) is applied to flap 902. In thisway, flap 902 can be used to protect cover glass 806. For example, coverassembly 900 can be magnetically attached to tablet device 900. Flap 902can then be placed upon and magnetically secured to cover glass 806 bythe magnetic interaction between magnetic attachment features 110 and216. Flap 902 can be detached from cover glass 806 by the application ofreleasing force F_(release) directly to flap 902. Releasing forceF_(release) can overcome the magnetic attraction between magneticattachment features 110 and 216. Hence, flap 902 can then move away fromcover glass 806 unhindered. In order to maintain a good magneticattachment between flap 902 and magnetic attachment feature 110, flap902 can include a number of magnetic elements. Some of the magneticelements in flap 902 can interact with corresponding magnetic elementsin magnetic attachment feature 110. The net magnetic attractive forcegenerated between the magnetic elements can be strong enough to preventinadvertent release of flap 902 from cover glass 806 during normalhandling. The net magnetic attractive force, however, can be overcome byreleasing force F_(release). It should be noted that using at least twomagnetic attachment features 110 on either side of tablet device 800,lateral movement of cover 900 (also referred to as racking) can beessentially eliminated.

In some embodiments, flap 902 can be unitary in appearance by which itis meant that flap 902 can appear as a single unit such that flap 902can bend slightly if formed of flexible material. However, in othercases, flap 902 can include a number of segments joined to adjacentsegments by associated folding regions that permit the segments to foldindependently of each other as well as with respect to tablet device800. Accordingly, FIG. 10A shows a top view of a specific embodiment ofcover assembly 900 in the form of cover assembly 1000. Cover assembly1000 can include body 1002. Body 1002 can have a size and shape inaccordance with cover glass 806. Body 1002 can be formed from a singlepiece of foldable or pliable material. Body 1002 can also be dividedinto segments separated from each other by a folding region. In thisway, the segments can be folded with respect to each other at thefolding regions.

In one embodiment, body 1002 can be formed of layers of materialattached to one another forming a laminate structure. Each layer cantake the form of a single piece of material that can have a size andshape in conformance with body 1002. Each layer can also have a size andshape that correspond to only a portion of body 1002. For example, alayer of rigid or semi-rigid material about the same size and shape of asegment can be attached to or otherwise associated with the segment. Inanother example, a layer of rigid or semi-rigid material having a sizeand shape in accordance with body 1002 can be used to provide segmentedcover assembly 1000 as a whole with a resilient foundation. It should benoted that the layers can each be formed of materials having desiredproperties. For example, a layer of segmented cover assembly 1000 thatcomes in contact with delicate surfaces such as glass can be formed of asoft material that will mar or otherwise damage the delicate surface. Inanother embodiment, a material such as micro-fiber can be used that canpassively clean the delicate surface. On the other hand, a layer that isexposed to the external environment can be formed of a more rugged anddurable material such as plastic or leather.

In a specific embodiment, body 1002 can be partitioned into a number ofsegments that can be widely varied. In the embodiment shown in FIG. 10A,segmented body 1002 can be partitioned into three segments, segments1004, 1006, and 1008 each coupled to an adjacent segment by thinner,foldable portions 1010. Each of the segments 1004-1008 can include oneor more inserts disposed therein. By way of example, the segments caninclude a pocket region where the inserts are placed or alternativelythe inserts may be embedded within the segments (e.g., insert molding).If pockets used, the pocket region can have a size and shape toaccommodate corresponding inserts. The inserts can have various shapesbut are most typically shaped to conform to the overall look ofsegmented body 1002 (e.g., rectangular). The inserts can be used toprovide structural support for segmented body 1002. That is, the insertscan provide stiffness to the cover assembly. In some cases, the insertsmay be referred to as stiffeners. As such, cover assembly 1000 isrelatively stiff except along the foldable regions that are thinner anddo not include the inserts (e.g., allows folding) making segmented coverassembly 1000 more robust and easier to handle. In one embodimentsegments 1004, 1006, and 1008 can have a size relationship to each othersuch that a segments 1004-1008 can be used to form a triangular supportstructure. The triangular support structure can be used to enhance auser experience of tablet device 800.

For example, if segmented body 1002 is constructed to have threeindependently foldable segments (segment 1004, segment 1006, and segment1008), a triangular structure can be formed by coupling segment 1004 andsegment 1008 (using magnets as described below or simply frictioncoupling). It should be noted that the properties of the triangularstructure can vary in accordance with the relative sizes of the segments1004, 1006, and 1008. In other words, when segments 1004, 1006, and 1008are about equal in width, then the triangular structure can take theform of an equilateral triangle, whereas when two segments are about ofequal width, then the triangular structure can take on the shape of anisosceles triangle. In this way, the triangular structure can be shapedfor a particular purpose. For example, in one configuration thetriangular structure can be used to support tablet device 800 in a moviemode or in a keyboard mode.

In one embodiment, segmented body 1002 can include a number of magnetssome of which can be used to form the triangular structure. For example,segment 1004 can include first edge attach magnets 1012 linearly arrayedalong first edge 1014 of segmented body 1002 whereas segment 1008 caninclude second edge attach magnets 1016 linearly arrayed along secondedge 1018 opposite to first edge 1014. In this embodiment, first edgeattach magnets 1012 and second edge attach magnets 1016 have a one toone correspondence in which each first edge attach magnet 1012 can beassociated with a corresponding one of second edge attach magnets 1016.Moreover, in order to create a maximum magnetic attractive force betweenfirst edge attach magnets 1012 and second edge attach magnets 1016, eachmagnet pair can exhibit opposite magnetic polarities. For example, whenfirst edge attach magnets 1012 are arranged in first polarity pattern(alternating) M₁ {P1, P2, P1, P2, P1, P2, P1, P2}, then second edgeattach magnets 1016 can be arranged in complementary priority pattern M₂{P2, P1, P2, P1, P2, P1, P2, P1}. In this way, a maximum magneticattachment force can be realized between the two magnetic arrays whileminimizing magnetic fringe effects at the ends of the magnetic arrays.In one embodiment, first edge attach magnets 1012 and second edge attachmagnets 1016 can have dimensions of approximately (L×W×H) of 10 mm×5mm×8 mm formed of neodymium (N35SH) grade magnets. It should be notedthat the number of edge attach magnets can vary from as few as two tomore than 16.

It should be noted that in some cases, it can be desirable to constraina magnetic field provided by first edge attach magnets 1012 and secondedge attach magnets 1014 in order to avoid or at least control adversemagnetic affects on sensitive magnetic circuits such as compass 120(whose position is indicated in relation to first edge attach magnets1012 when segmented body 1002 is in the fully closed configuration). Inorder to control the adverse affects of the magnetic field generated byfirst edge attach magnets 1012, field shaping magnets 1022 can be placedin positions that can reduce a magnetic offset experienced by compass120. Moreover, as shown in insert 1024, first edge attach magnets 1012(as well as second edge attach magnets 1016) can be shaped in such a waythat leakage magnetic flux Φ_(leakage) between the constituent magnetscan be substantially reduced. In the embodiment shown in insert 1024,magnets 1026 are trapezoidal in form that limits the amount of magneticflux Φ_(leakage). In this way, the magnetic offset at compass 120 causedby first edge attach magnets 1012 can be maintained with an acceptablerange. For example, the magnetic offset at compass 120 from edge attachmagnets 1012 can be on the order of 10° or less at a reference location.

One approach to forming at least one triangular support structure can beto simply friction couple segment 1004 and segment 1008. By frictioncouple it is meant that surface friction created between segments 1004and 1008 when brought in direct contact can be sufficient to maintainthe triangular structure even when used to support tablet device 800 inthe movie mode or the keyboard mode. Alternatively, the triangularstructure can be formed by bringing first edge attach magnets 1012 inproximity to second edge attach magnets 1016 thereby forming a magneticcircuit. It should be noted that in some embodiments, first edge attachmagnets 1012 and second edge attach magnets 1016 are not required tooverlay one another but merely be in proximity separated by distance “d”(shown in FIG. 11) from one another to create the magnetic circuit.Therefore, by creating the magnetic circuit configured to maintain theintegrity of the triangular structure, the triangular structure can beused for multiple purposes to enhance the functionality of tablet device800.

Segmented cover 1000 can also include holding magnets 1028 and 1030 thatcan be used to maintain segmented cover 1000 in a fixed position inrelation to display 806 in the fully closed configuration. In otherwords, holding magnets 1028 and 1030 can reduce or even eliminatemovement of cover 1000 from “side to side” (sometimes referred to as“racking”). In one embodiment, holding magnet 1030 can be oversized inrelation to holding magnet 1028. In this way, first portion 1030 a ofholding magnet 1030 (i.e., that portion of holding magnet 1030 that doesnot function as an edge attach magnet) can cooperate with holding magnet1028 to reduce racking of cover 1000 whereas edge attach portion 1030 bof holding magnet 1030 can function as part of first edge attach magnets1012.

In some cases, cover 1000 can also include magnets used to triggermagnetic sensors in tablet device 900. For example, segment 1004 caninclude first sensor magnet 1032 and segment 1006 can include secondsensor magnet 1034. It should be noted that in some embodiments, firstsensor magnet 1032 can be over-sized to prevent a false open conditionin which tablet device 800 activates the display assembly even thoughbody 1002 remains in the fully closed configuration. The false opencondition can be triggered when body 1002 laterally moves (i.e.,racking) to such an extent that a sensor disposed in tablet 800 can nolonger detect the magnetic field generated by first sensor magnet 1032causing the processor in tablet device 1032 to alter the operating stateto active display mode. Therefore, the combination of oversizing offirst sensor magnet 1032 and using holding magnets 1028 and 1030 toreduce racking, the incidence of false open condition can be greatlyreduced.

In this arrangement, first sensor magnet 1032 can be detectable by amagnetically sensitive circuit (such as a Hall Effect sensor, or HFX)disposed within tablet 800. In particular, the HFX can detect a magneticfield provided by sensor magnets 1032 and 1034 through protective layer806. In this way, a processor in tablet device 800 can use magneticdetection information to determine a spatial relationship between cover1000 and tablet 800. More specifically, the detection information canprovide an indication that segment 1004 is folded away from tablet 1000(when sensor magnet 1032 is not detected and sensor magnet 1034 isdetected). In this way, the processor can alter operation of tabletdevice 800 in accordance with the spatial relationship between cover1000 and tablet 800. For example, when the processor determines thatonly segment 1004 is folded away to reveal a corresponding portion ofdisplay assembly 804, then the processor can change the operation oftablet 800 to provide visual content only by the revealed portion ofdisplay assembly 804 in what is referred to as peek mode. In someembodiments, tablet device 800 can operate in what is referred to asextended peek mode when sensor magnets 1032 and 1034 are not detectedbut the processor can determine that cover 1000 is magnetically attachedto tablet 800 (in other words, segments 1004 and 1006 are folded awayfrom tablet device 800 to reveal a corresponding portion of displayassembly 804, but segment 1008 remains in place). In this way, tabletdevice 800 can present visual content in only that portion of displayassembly 804 that is viewable (corresponding to folded away segments1004 and 1006).

Cover 1000 can magnetically attach to tablet device 800 using flexiblehinge assembly 1036 that can include flexible hinge 1038 and magneticassembly 1040. Flexible hinge assembly 1036 can be integrated in thesense that there flexible hinge assembly 1036 is formed as part ofsegmented cover 1000. In some embodiments, flexible hinge assembly 1036can be formed of the same material (fabric, leather, etc.) as is used toform a top portion of segmented cover 1000. In this way, the visualeffect can be one of continuity when viewing segmented cover 1000.Further enhancing the sense of continuity is the wrap around nature offlexible hinge 1036. By wrap around it is meant that material that formsbody 1002 (and in particular a top portion formed of fabric, forexample) can continue beyond edge 1018 (sometimes referred to as a tail)to form flexible hinge 1038 that can wrap around magnetic assembly 1040.In this way, a sense of continuity between body 1002 and flexible hingeassembly 1036 can be achieved.

Flexible hinge assembly 1036 can include flexible hinge 1038 coupled tomagnetic assembly 1040 configured to magnetically attach to magneticattachment feature 108 in tablet device 800. In one embodiment, magneticassembly 1040 can include a plurality of magnets configured to form amagnetic attachment with corresponding magnets in magnetic attachmentfeature 108. For example, FIG. 10B shows a representation of possiblemagnet arrays used to magnetically attach cover 1000 and tablet device800. In one embodiment, magnetic assembly 1040 can include magneticarray 1042 arranged in alternating pattern M3 as follows:

M3: {[P1, P2, P1], [P1, P2], [P2, P1], [P1,P2], [P2,P1,[P1,P2][P2,P1,P2]}

(where brackets [ ] indicate physically grouped magnets).

On the other hand, magnetic attachment feature 108 disposed in tabletdevice 800 can include a corresponding magnetic array 1044 arranged in amanner that is complementary to alternative pattern M3. By complementaryit is meant that magnetic polarities are inverted in that a magnethaving a P1 polarity will be paired with a magnet having a P2 polarityand so forth. In this way, a maximum amount of magnetic attractive forcebetween the two magnets can be realized with a minimum of magneticfringing effects at either end of the magnetic array.

However, in still other embodiments as represented by magnetic array1046, specific magnets can be replaced by ferromagnetic blocks in orderto conserve on the number of magnets used for magnetic attachment. Forexample, in one embodiment, a reduced number of magnets can be used inmagnetic attachment feature 108 by replacing some magnets withferromagnetic blocks (B) and can be arranged in polarity pattern M4 asfollows:

M4: {[P1, B, P1], [P1, P2], [P2, P1], [P1,P2], [P2,P1, [P1,P2][P2,B,P2]}

where B represents a ferromagnetic block formed of ferromagneticmaterial such as 1010 steel. It should be noted that the arrangement ofmagnets in either magnetic attachment feature 108 or magnetic assembly1040 can be widely varied. Any limitations can be due primarily to therelationship between the magnetic arrays and the desired properties ofthe magnetic attachment.

FIG. 11 also illustrates representative magnetic interaction betweenedge attach magnets 1012 and 1016 in accordance with magnetic circuit1102. Magnetic circuit 1102 can be associated with magnetic attractionforce F_(attraction). Magnetic attraction force 1104 can correspond withmagnetic flux density associated with magnetic field lines 1106. Forexample, the magnetic flux density associated with magnetic circuit 1102in region A (where magnets 1012 and 1016 are closest together) can begreater than the magnetic flux density in region B where magnets 1012and 1016 are further apart. In this way, magnetic attraction force 1104between segment 1008 and 1004 can be strongest in region A. Moreover, amagnetic interaction between magnet 1012 and magnets 1050 and 108 can besuch that net repulsive force Fr can be applied to segment 1004 thatincreases the net attachment force between segments 1004 and 1008. Inother words, the total attachment force between segments 1004 and 1008can be the aggregate of magnetic attraction force F_(attraction) andmagnetic repulsion force F_(repulsion).

FIGS. 12A-12D show representative cross sectional views of segmentedcover assembly 1000/tablet device 800 along line AA shown in FIG. 10A.In particular, FIG. 12A shows cover assembly 1000 in fully closedconfiguration 1200 in which interior surface 1204 of cover assembly 1000comes in full contact with cover glass 806 of tablet device 800. Infully closed configuration 1200, Hall Effect sensor 118-1 can detect amagnetic field provided by sensor magnet 1032. Concurrently Hall Effectsensor 118-2 can detect a magnetic field provided by sensor magnet 1034.In this way, the processor can use the detection information provided byHall Effect sensors 118-1/118-2 to determine a folded configuration ofcover 1000 and the associated spatial relationship between cover 1000and tablet device 800. For example, using the detection information fromHall Effect sensors 118-1/118-2, the processor determines that cover1000 is in fully closed configuration 1200 where interior surface 1204of cover 1000 is in full contact with cover glass 806. In this way, oncethe processor has determined the spatial relationship between cover 1000and tablet device 800, the processor can cause tablet device 800 tooperate in a manner in accordance with the determined spatialrelationship. For example, when the processor determines that cover 1000is in fully closed configuration 1200, the associated spatialrelationship is one where interior surface 1204 is in full contact withcover glass 806 thereby rendering the display and any visual contentpresented thereon as being un-viewable. Accordingly, the processor candirect that tablet device 800 disable or at least prevent visual frombeing presented by the un-viewable display. This can be referred to as asleep mode.

FIG. 12B shows partially open configuration 1202 where segment 1004 isfolded away from cover glass 806 in such a way that portion 806-1 ofdisplay is rendered viewable. In partially open configuration 1202, HallEffect sensor 118-1 can not detect the magnetic field provided by sensormagnet 1032 since any magnetic field from magnet 1032 at Hall Effectsensor 118-1 is not greater that a minimum detection threshold. In thiscase, the processor can use detection information from Hall Effectsensor 118-2 and Hall Effect sensor 118-2 to deduce that only segment1004 is folded away from cover glass 806 revealing portion 806-1 ofcover glass 806. In this way, only that portion of the displaycorresponding to portion 806-1 is viewable. In this situation, theprocessor can cause tablet device 800 to operate in a manner inaccordance with partially open configuration 1202. In one embodiment,tablet device 800 can operate in such a way that although the displayremains fully active, visual content is presented only at the viewableportion of the display that corresponds to portion 806-1. In analternative embodiment, all but the viewable portion of the display canbe de-activated. In this way, power can be conserved. In yet anotheralternative embodiment, visual content such as a graphical userinterface, or GUI, can be altered in such a way to accommodate thereduced visual display area. For example, an amount of video resourcesallocated to display the GUI can be modified to take into account thereduced display area. The video resources can include number of pixels,pixel depth, and so forth.

It should be noted that in the case where neither Hall Effect sensors118-1 or 118-2 detect either sensor magnet 1032 or 1034, then cover 1000can be in one of two possible states. A first state being the fully openconfiguration in which substantially all of cover glass 806 is revealedsuch that substantially of the display assembly can present visualcontent. However, a second state (also referred to as extended peekmode) can be associated with segments 1004 and 1006 being folded awayfrom cover glass 806 but segment 1008 remains in place. The fully openconfiguration can be distinguished from the extended peek state bydetermining if cover 1000 is magnetically attached to tablet device 800.This determination can be accomplished using magnetically sensitivecircuits such as compass 120. If a magnetic offset consistent with thepresence of magnetic attachment feature 108 being in active mode isexperienced by compass 120, then the processor can infer that cover 1000is magnetically attached to tablet device 800 and in so doing can alterthe operation of tablet device 800 in accordance with the extended peekmode (such as presenting visual content at a viewable part of thedisplay assembly).

FIGS. 12C and 12D show embodiments whereby cover 1000 is folded in sucha way that interior surface 1204 is in contact with rear surface 808 oftablet device 800 in first reverse folded configuration 1206. Reversefolded configuration 1206 can be useful in those situations where tabletdevice 800 includes a camera or other such imaging device. In this way,a user can hold tablet device 800 using reverse folded configuration1206 enabling use the display assembly as a viewfinder that can be usedto compose an image or video. It should be noted that magnetic detectioncircuits such as Hall Effect sensor 118-1 and Hall Effect sensor 118-2can be configured in such a way that in reverse folded configuration1206, only one of the magnetic detection circuits can detect acorresponding magnet in cover 1000. For example, in reverse foldedconfiguration 1206, Hall Effect sensor 118-1 can detect magnet 1032whereas Hall Effect sensor 118-2 can not detect magnet 1034. Thisvariation in detectability can be accomplished by, for example, varyingthe magnetic properties of the magnets or by providing a magnetic shieldthat reduces a magnetic field that emanates from rear surface 806 in thevicinity of Hall Effect sensor 118-2.

Accordingly, when Hall Effect sensor 118-1 detects magnet 1032 and HallEffect sensor 118-2 does not detect magnet 1034, then tablet device 800can operate in accordance with first reverse folded configuration 1206.For example, in reverse folded configuration 1206, tablet device 800 canoperate in a manner that facilitates use of the display assembly as aview finder. In an alternative embodiment shown in FIG. 12D in whichcover 1000 is in second reverse folded configuration also referred to asrear camera folded configuration 1208, neither Hall Effect sensor 118-1nor Hall Effect sensor 118-2 can detect magnets 1032 or 1034. In thisarrangement, an attachment detection device (such as compass 120) can beused to detect if cover 1000 is magnetically attached to tablet device800. In this way, when it is determined that tablet device 800 isattached to cover 1000 and cover 1000 is in second reverse foldedconfiguration 1208, then tablet device 800 can operate accordingly.Table 1 summarizes some of the relationships between detection signalsprovided by HFX sensors 118-1 and 118-2 and the corresponding spatialrelationship between cover 1000 and tablet device 800 in terms of afolded configuration of cover 1000.

TABLE 1 Folded Configuration HFX 118-1 Detection HFX 118-2 DetectionFully Closed (D)etect (D)etect Peek Mode (N)o (D)etect (D)etect FirstReverse Folded (D)etect (N)o (D)etect Reverse Camera Folded (N)o(D)etect (N)o (D)etect

In addition to providing protection to tablet device 800, segmentedcover assembly 1000 can be manipulated to form useful supportstructures. Accordingly, FIGS. 13 through 15 show useful arrangements ofcover assembly 1000 in accordance with the described embodiments.

FIGS. 13A-13B show a side view of a segmented cover configured tosupport a tablet device in a keyboard state. As shown in FIGS. 13A and13B, segmented cover assembly 1000 can be folded into first triangularstructure 1300 by forming in one embodiment, magnetic circuit 1102 bybringing segment 1004 and 1008 in proximity to each other (it should benoted that a friction coupling between the segments can also suffice toform triangular structure 1300). Triangular structure 1300 can be formedthat can be used in many ways to augment tablet device 800. For example,triangular structure 1300 can be used to support tablet device 800 insuch a way that a touch sensitive surface disposed beneath cover glass806 is positioned relative to a support surface at an ergonomicallyadvantageous angle. In this way, using the touch sensitive surface canbe a user friendly experience. This is particularly relevant in thosesituations where the touch sensitive surface is used over an extendedperiod of time. For example, a virtual keyboard can be presented at thetouch sensitive surface. The virtual keyboard can be used to input datato tablet device 800. By using triangular structure 1300 to supporttablet device 800 at the ergonomically friendly angle, the deleteriouseffects of repetitive movements can be reduced or even eliminated. Inthe described embodiment, presentation angle θ can be in the range of 5°to 15°. FIG. 13B shows an alternative embodiment where cover 1000 isfolded into second triangular structure 1302 in which segment 1004 isviewable in contrast to first triangular structure 1300 where segment1004 was obscured from view by tablet device 800 and segment 1008 isviewable.

FIGS. 14A and 14B shows another folded configuration of segmented coverassembly 1000 in which triangular support structure 1400 can be used tosupport tablet device 800 in a viewing state. By viewing state it ismeant that triangular structure 1400 can support tablet device 800 insuch a way that the display assembly can present visual content (visual,stills, animation, etc.). For example, in a first display configurationtriangular support structure can support tablet device 800 such that thedisplay assembly can present visual content at a presentation angle ofabout 65° to about 85°. In this “kickstand” state, visual content can bepresented for easy viewing. FIG. 14B illustrates another arrangement ofcover 1000 in the form of triangular support structure 1402 in whichtablet device 800 can be supported in manner such that the displayassembly presents visual content. FIG. 14C shows a front view of tabletdevice 800 supported in the viewing state in accordance with thedescribed embodiments.

FIGS. 15A-15B show configuration 1500 of cover assembly 1000 and tabletdevice 800 illustrating what is referred to as a peek mode of operationof tablet device 800. More particularly, when segment 1004 is liftedfrom glass cover 806, sensors in tablet device 800 can detect thatsegment 1004 and only that segment has been lifted from glass layer 806.Once detected, tablet device 800 can activate only the exposed portion1502 of the display. For example, tablet device 800 can utilize a HallEffect sensor to detect that segment 1004 has been lifted from glasscover 806. Additional sensors, such additional Hall Effect sensor orother type sensors such as optical sensors (ambient light sensor, forexample) can then detect if only segment 1004 has been lifted or ifadditional segments have been lifted.

As shown in FIG. 15B, when tablet device 800 has determined that onlysegment 1004 has been lifted, then tablet device 800 can changeoperating state to “peek” state in which only the exposed portion 1502of the display actively presents visual content in the form of icons1504. Hence, information in the form of visual content such as time ofday, notes, and so forth can be presented for viewing on only thatportion of display viewable. Once the sensors detect that segment 1004has been placed back on glass layer 806, tablet device 800 can return tothe previous operational state such as a sleep state. Furthermore, inanother embodiment, when an icon arranged to respond to a touch isdisplayed, then that portion of a touch sensitive layer corresponding tothe visible portion of the display can also be activated.

Furthermore, as additional segments are lifted from cover glass 806 tofurther expose additional portions of cover glass 806, additionalportions of the display can be activated corresponding to the liftedsegments. In this way, in the “extended” peek mode, additional visualinformation can be presented in the portions of the display activated.In this way, as segments are lifted from cover glass 806, additionalsegments of the display can be activated providing the extended peekmodes in accordance with the number of foldable segments. Alternatively,the tablet device 900 can respond to the signals from the Hall Effectsensor(s) by simply powering up the display when the flap is moved awayfrom the display and power down (sleep) when the display is covered bythe flap.

FIG. 16 shows an exploded view 1600 of segmented cover 1000. Bottomlayer 1602 can come in direct contact with a protected surface such as acover glass for a display. Bottom layer 1602 can be formed of a materialthat can passively clean the protected surface. The material can be, forexample, a microfiber material. Bottom layer 1602 can be attached tostiffening layer 1604 formed of resilient material such as plastic.Stiffening layer 1604 can, in turn, be adhesively attached to inserts1606 to form a laminate structure. Inserts 1606 can be formed ofresilient material such as plastic. It should be noted that although notshown, some of inserts 1606 can accommodate embedded components such asholding magnet 1028, sensor magnets 1032 and 1034, and so on. Edgesupport ring 1608 can be used to provide lateral stability to cover1000. Magnetic assembly 1040 can be attached to flexible hinge portion1038 using adhesive layers 1610. Magnetic assembly 1040 can includemagnets 1050 supported by span 1608. Span 1612 can be formed of a strongresilient material such as 304 SUS. It should be noted that in someembodiments, metal portions of 1612 can be sand-blasted in order tofacilitate bonding between span 1612 and protective layer 1602 usingadhesive layers 1616. In a particular embodiment, span 1612 can beattached to protective layers 1602 using pressure sensitive adhesive, orPSA. An additional laminate structure can be formed of resilientmaterial 1616 and top layer 1618. In some embodiments, an interveninglayer of material can be provided having a knitted structure that canaid in the attachment of top layer 1618 to resilient material 1616. Toplayer 1618 can be formed of many materials such as plastic, leather, andso forth in keeping with the overall look and feel of tablet device 800.In order to provide additional structural support, edge stiffener ring1608 can be used to reinforce edges of cover 1000. Edge stiffener ring1608 can be formed of plastic or other rigid or semi-rigid material. Itshould be noted that in order to preserve the aesthetic look of cover1000, cosmetic finish 1620 can be used to cover portions of magneticassembly 1040.

FIG. 17 is a block diagram of an arrangement 1700 of functional modulesutilized by an electronic device. The electronic device can, forexample, be tablet device 900. The arrangement 1700 includes anelectronic device 1702 that is able to output media for a user of theportable media device but also store and retrieve data with respect todata storage 1704. The arrangement 1700 also includes a graphical userinterface (GUI) manager 1706. The GUI manager 1706 operates to controlinformation being provided to and displayed on a display device. Thearrangement 1700 also includes a communication module 1708 thatfacilitates communication between the portable media device and anaccessory device. Still further, the arrangement 1700 includes anaccessory manager 1710 that operates to authenticate and acquire datafrom an accessory device that can be coupled to the portable mediadevice.

FIG. 18 is a block diagram of an electronic device 1750 suitable for usewith the described embodiments. The electronic device 1750 illustratescircuitry of a representative computing device. The electronic device1750 includes a processor 1752 that pertains to a microprocessor orcontroller for controlling the overall operation of the electronicdevice 1750. The electronic device 1750 stores media data pertaining tomedia items in a file system 1754 and a cache 1756. The file system 1754is, typically, a storage disk or a plurality of disks. The file system1754 typically provides high capacity storage capability for theelectronic device 1750. However, since the access time to the filesystem 1754 is relatively slow, the electronic device 1750 can alsoinclude a cache 1756. The cache 1756 is, for example, Random-AccessMemory (RAM) provided by semiconductor memory. The relative access timeto the cache 1756 is substantially shorter than for the file system1754. However, the cache 1756 does not have the large storage capacityof the file system 1754. Further, the file system 1754, when active,consumes more power than does the cache 1756. The power consumption isoften a concern when the electronic device 1750 is a portable mediadevice that is powered by a battery 1774. The electronic device 1750 canalso include a RAM 1770 and a Read-Only Memory (ROM) 1772. The ROM 1772can store programs, utilities or processes to be executed in anon-volatile manner. The RAM 1770 provides volatile data storage, suchas for the cache 1756.

The electronic device 1750 also includes a user input device 1758 thatallows a user of the electronic device 1750 to interact with theelectronic device 1750. For example, the user input device 1758 can takea variety of forms, such as a button, keypad, dial, touch screen, audioinput interface, visual/image capture input interface, input in the formof sensor data, etc. Still further, the electronic device 1750 includesa display 1760 (screen display) that can be controlled by the processor1752 to display information to the user. A data bus 1766 can facilitatedata transfer between at least the file system 1754, the cache 1756, theprocessor 1752, and the CODEC 1763.

In one embodiment, the electronic device 1750 serves to store aplurality of media items (e.g., songs, podcasts, etc.) in the filesystem 1754. When a user desires to have the electronic device play aparticular media item, a list of available media items is displayed onthe display 1760. Then, using the user input device 1758, a user canselect one of the available media items. The processor 1752, uponreceiving a selection of a particular media item, supplies the mediadata (e.g., audio file) for the particular media item to a coder/decoder(CODEC) 1763. The CODEC 1763 then produces analog output signals for aspeaker 1764. The speaker 1764 can be a speaker internal to theelectronic device 1750 or external to the electronic device 1750. Forexample, headphones or earphones that connect to the electronic device1750 would be considered an external speaker.

The electronic device 1750 also includes a network/bus interface 1761that couples to a data link 1762. The data link 1762 allows theelectronic device 1750 to couple to a host computer or to accessorydevices. The data link 1762 can be provided over a wired connection or awireless connection. In the case of a wireless connection, thenetwork/bus interface 1761 can include a wireless transceiver. The mediaitems (media assets) can pertain to one or more different types of mediacontent. In one embodiment, the media items are audio tracks (e.g.,songs, audio books, and podcasts). In another embodiment, the mediaitems are images (e.g., photos). However, in other embodiments, themedia items can be any combination of audio, graphical or visualcontent. Sensor 1776 can take the form of circuitry for detecting anynumber of stimuli. For example, sensor 1776 can include a Hall Effectsensor responsive to external magnetic field, an audio sensor, a lightsensor such as a photometer, and so on.

The magnetic attachment feature can be used to magnetically attach atleast two objects. The objects can take many forms and perform manyfunctions. When magnetically attached to each other, the objects cancommunicate and interact with each other to form a cooperative system.The cooperating system can perform operations and provide functions thatcannot be provided by the separate objects individually. For example, atleast a first object and a second object can be magnetically attached toeach other such that the first object can be configured to provide asupport mechanism to the second object. The support mechanism can bemechanical in nature. For example, the first object can take the form ofa stand that can be used to support the second object on a workingsurface such as a table. In another example, the first object can takethe form of a hanging apparatus. As such, the first object can be usedto hang the second object that can then be used as a display forpresenting visual content such as a visual, still images like a picture,art work, and so on. The support mechanism can also be used as a handlefor conveniently grasping or holding the second object. This arrangementcan be particularly useful when the second object can present visualcontent such as images (still or visual), textual (as in an e-book) orhas image capture capabilities in which case the second object can beused as an image capture device such as a still or visual camera and thefirst object can be configured to act as a support such as a tripod orhandle.

The various aspects, embodiments, implementations or features of thedescribed embodiments can be used separately or in any combination.Various aspects of the described embodiments can be implemented bysoftware, hardware or a combination of hardware and software. Thedescribed embodiments can also be embodied as computer readable code ona non-transitory computer readable medium. The computer readable mediumis defined as any data storage device that can store data which canthereafter be read by a computer system. Examples of the computerreadable medium include read-only memory, random-access memory, CD-ROMs,DVDs, magnetic tape, and optical data storage devices. The computerreadable medium can also be distributed over network-coupled computersystems so that the computer readable code is stored and executed in adistributed fashion.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not target to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

The advantages of the embodiments described are numerous. Differentaspects, embodiments or implementations can yield one or more of thefollowing advantages. Many features and advantages of the presentembodiments are apparent from the written description and, thus, it isintended by the appended claims to cover all such features andadvantages of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, the embodimentsshould not be limited to the exact construction and operation asillustrated and described. Hence, all suitable modifications andequivalents can be resorted to as falling within the scope of theinvention.

What is claimed is:
 1. A magnetic system suitable for use in aprotective cover having a foldable flap formed of a layer of finishingmaterial, the protective cover used in cooperation with a tablet devicehaving a display, comprising: a first array of edge attach magnetsaligned with a first edge of the foldable flap cover; a second array ofedge attach magnets aligned with a second edge of the foldable flap andaligned with the first array of edge attach magnets, wherein the firstand second array of edge attach magnets form a magnetic circuit thatmaintains a folded configuration of the protective cover; and aplurality of field shaping magnets disposed at selected locations on themagnetic cover such that magnetic fields from the plurality of fieldshaping magnets interact with magnetic fields from the first array ofedge attach magnets to effectively provide essentially a null magneticfield at least one predefined position corresponding to a magneticallysensitive circuit disposed in the tablet device.
 2. The magnetic systemas recited in claim 1, wherein the magnetically sensitive circuit is amagnetic compass.
 3. The magnetic system as recited in claim 2, whereinat least some of the first edge attach magnets are shaped to preventinter-magnet flux leakage, the inter-magnet flux leakage causing amagnetic offset at the magnetic compass.
 4. The magnetic system asrecited in claim 1, wherein the magnetic circuit is formed whencorresponding ones of the first array of edge attach magnets and thesecond array of edge attach magnets are brought in proximity to eachother and do not overlap.
 5. The magnetic system as recited in claim 1,further comprising: an anti-racking magnet configured to prevent lateralmovement of the protective cover in relation to the tablet device whenthe protective cover and the tablet device are attached to each other.6. The magnetic system as recited in claim 5, wherein a portion of atleast one of the first array of edge attach magnets acts as theanti-racking magnet.
 7. The magnetic system as recited in claim 1,further comprising: a first sensing magnet disposed at a first positionin the protective cover, the first sensing magnet being detectable by acorresponding sensor disposed in the tablet device corresponding to thefirst position.
 8. The magnetic system as recited in claim 7, furthercomprising: a second sensing magnet disposed at a second position in theprotective cover different from the first position, the second sensingmagnet being detectable by a corresponding sensor disposed in the tabletdevice corresponding to the second position.
 9. The magnetic system asrecited in claim 8, wherein the second sensing magnet is larger than thefirst sensing magnet such that the second sensing magnet remainsdetectable by the corresponding sensor in the tablet device when theprotective cover and the tablet device are attached to each other. 10.The magnetic system as recited in claim 1, further comprising: amagnetic attachment array disposed in a hinge portion integrally formedfrom a continuation of the layer of finishing material, the magneticattachment array configured to magnetically interact with acorresponding magnetic attachment array in the tablet device tomagnetically attach the protective cover and the tablet device.
 11. Aconsumer system, comprising: a tablet device, comprising: a housinghaving a front opening, a display assembly disposed within the frontopening, the display assembly comprising: a display, and a topprotective layer disposed adjacent to the display, a plurality ofsensors configured to detect a corresponding stimulus, and a firstmagnetic attachment system disposed within and secured to an inside sidewall of the housing, the first magnetic attachment system configured toprovide a variable magnetic surface at an exterior of the housing inresponse to an appropriately configured external magnetic field; and acover, comprising: a segmented flap formed of a layer of protectivefinishing material having a size and shape in accordance with thedisplay, an integrated hinge comprising a flexible hinge formed of acontinuous layer of the layer of finishing material, and a secondmagnetic attachment unit configured to provide the appropriatelyconfigured magnetic field to the first magnetic attachment system,wherein the first magnetic attachment system interacts with theappropriately configured magnetic field by transitioning from aninactive state to an active state, wherein in the active state the firstmagnetic attachment system provides a first magnetic surface at anexterior of the housing suitable for forming a magnetic attachment withthe second magnetic attachment system.
 12. The consumer system asrecited in claim 11, the first magnetic attachment system comprising: aplurality of magnets arranged in a first polarity order; and a magneticshield disposed between each of the plurality of magnets and the insideside wall of the housing, the magnetic shield preventing magnetic fluxfrom extending to the exterior surface of the housing when the firstmagnetic attachment system is in an inactive state.
 13. The consumersystem as recited in claim 12, the second magnetic attachment systemcomprising: a plurality of magnets at least some of which correspond tothe plurality of magnets in the first magnetic attachment system andhaving opposite polarity.
 14. The consumer system as recited in claim13, the second magnetic attachment system as recited in claim 13,further comprising ferromagnetic blocks at those locations that do nothave magnets that correspond to those in the first magnetic attachmentsystem.
 15. The consumer system as recited in claim 14, wherein in theactive state, the magnetic shield is over-saturated and does not preventthe magnetic attachment between the tablet device and the protectivecover.
 16. A method of magnetically attaching a tablet device comprisinga housing and a first magnetic attachment system having a plurality ofmagnets and a magnetic shield disposed between the plurality of magnetsand an interior of a first side wall of the housing and a protectivecover having a second magnetic attachment system, comprising: causingthe first magnetic attachment system to transition from an inactivestate to an active state; and forming a magnetic attachment between thefirst magnetic attachment system and the second magnetic attachmentsystem in response to the transition to the active state.
 17. The methodas recited in claim 16, causing the first magnetic attachment system totransition to the active state, comprising: providing an appropriatelyshaped magnetic field that interacts with the magnetic field from thefirst magnetic attachment system in the inactive state; over-saturatinga magnetic shield, and forming the magnetic attraction through theover-saturated magnetic shield.
 18. The method as recited in claim 17,wherein the second magnetic attachment system comprises a plurality ofmagnets that align with corresponding ones of the first plurality ofmagnets in a complementary polarity order.
 19. The method as recited inclaim 18, wherein at least some of the second plurality of magnets arereplaced with a ferromagnetic block.
 20. The method as recited in claim16, in the inactive state, the magnetic shield is saturated and preventsexcess magnetic flux leakage at an exterior surface of the side wall.